Substation locking apparatus



Filed. Feb. 8, 1929 33 FIG. 2

25 gg 0 v /3 20 wil 3193/ /N [/5 N TOR 0. A \SHANN BVWMM A T TDRNEVPatented June 10, 1930 UNITED STATES PATENT OFFICE OSCAR A. SHANN, OFBROOKLYN, NEW YORK, ASSIGNOR TO BELL TELEPHONE LABORA- TORIES,INCORPORATED, OF NEW YORK, N. Y., A CORPORATION OF NEW YORK SUBSTATIONLOCKING APPARATUS Application filed February 8, 1929. Serial No.338,406.

This invention relates to locks or latches for telephone instruments andparticularly telephone instruments of the type commonly known ashandsets in which the transmitter and receiver are attached by asuitable handle and a stand containing a line connecting switch isprovided on which the handset is normally rested.

It is an object of this invention to prevent connection of a handsetinstrument with the line by an unauthorized person. A suitable locktherefor has been provided in the handset mounting which will preventmovement of the switch operating plunger when the handset is removedfrom the mounting.

One of the features of the invention is the locating of the lock withinthe base of the mounting where it is not only hidden from View but isrendered difficult of access.

Another feature is that the base plate of the mounting is secured to theupper portion by a specially designed screw which may be withdrawn onlywith a specially designed tool.

In Fig. 1, in the accompanying drawing a side view of the lower portionof a hand set mounting has been shown and in Fig. 2 a side view of afragmentary portion of the lower portion of a handset mounting. In eachof these figures a portion has been broken away so that various parts ofinterest in connection with this invention may be seen. In Fig. 3 a sideview of a handset.

mounting with a handset resting thereon is shown with certain portionsbroken away to disclose some of the parts and illustrate a modificationof the construction shown in Fig. 1. In Fig. 4 is shown a fragmentaryportion of one form of special screw which may be employed to secure thebase plate to the ,m'ountingland a key for turning the screw. It may bedesired in some instances to have an instrument which may be set inlocked or unlocked condition for an indefinite time or it may be desiredto have an instrument which may be unlocked for putting through a callbut which will autoinstrument may be set in locked or unlocked conditionfor an indefinite time, and in Fig. 2 an arrangement by which a handsettelephone instrument may be unlocked for the putting through of a call,but which upon completion of the call will be automatically restored tolocked condition. Means are also shown in Fig. 2 whereby the lock may beset in unlocked condition for an indefinite time.

Referring now more specifically to the various parts shown in thedrawing, 1 is the lower portion or casing of a handset mounting, 2 is anaperture in the casing for the accommodation of wires not shown butwhich are commonly lead into the casing, 3 is a fragment of the pillarportion and 4 is the'base plate of the handset mounting. The base plate4 is usually covered with felt or some textile material to preventmarring of a desk or table top when the handset is rested thereon ormoved across it. This base plate covering is shown at 5 and in crosssection at 6, and 15 held stretched over the base plate l by a splitring not shown but which is sprung within an upturned wall portion ofthe base plate Located within the casing 1 of the handset mounting,there is a bracket 7 which by a nut 8 is secured to a shank portion notshown but which extends downward within the casing 1 from the base ofthe pillar portion 3. Integral with the bracket 7 and extending downwardare arms 9 and 10. Arm 9 extends downward into close proximity to anembossing 11 formed in the base plate 4.

' An ear portion 12 of the arm 9 is drilled and threaded to receive ascrew 13 which passes through an aperture in the embossing 11 and servesto secure the base plate 4: to the arm 9 and hold the base plate at upagainst the lower portion 1 of the casing of the handset mounting.Secured to the arm 10 are the spring contact members 14.- which arecommon to handset mountings and through which signaling connection maybe established between the handset instrument and the line.

, Extending downward through the pillar 3 is a spring pressed plunger 15and secured to this plunger 15 are arm members 16 only one of which isshown, on the free end of which is secured an insulating button 17 ewhich when the plunger 15 is moved, serves to cause movement of thecontacts 14in awell known manner. Attached to the plunger 15 by a screw18 is an arm 19 which terminates at its free end in a hook or offsetportion 20. v

Secured to the inner face of the base plate a is a lock 21 having a bolt22 which when extended from the lock will engage the hook portion of thearm 19 and prevent upward movement of the plunger 15 and the springcontacts 1 1. A key 23 which may be inserted in the lock 21 throughsuitable openings in the textile base covering 5 and the base plate 4:is provided for withdrawing the lock bolt 22 from engagement with thehook portion 20 of the arm 19 or extending the bolt 22 to lock the arm19 and plunger 15 against upward movement according as desired.

As has been previously pointed out the base plate 4 is secured to theear portion 12 of the arm 9 and held against the casing 1 by a screw 13which passes through a suitable opening 24: in the textilebase covering5 and an opening in the embossing 11 and into the ear portion 12 of thearm 9. A

L ring 25 serves to prevent accidental dislodgment of the screw 13 fromthe base plate 4. To make the lock 21 which is'secured on. Y the innerfacefof the base plate 4 inaccessible to an unauthorized "person, thescrew 13 is provided "with a head portion which is not adapted foroperativeengagement by a conventional type of tool such as an ordinaryscrew-driver. The head of screw 13 shown in'Fig. 4 may be provided withindentations so that it may be operatively en-' gag'ed only by such forinstance, as a key 27 provided with lugsor pins -28-28 spaced to thesame spacing as the indentations 2626 and which will fit therein. I

In the foregoing has'b'een describedan arrangement by which, when ahandset is placed upon its mounting and the switch operating plunger 15is depressed, the switch operating "plunger may be locked againstmovement and 'the spring contacts 14. prevented from being moved toestablish sig pressed member and the arm 19 terminates at its free endin a round ended offset portion 20. By turning the key 23 the bolt 22may be withdrawn from engagement with the arm 19 and the spring pressedplunger 15 allowed to rise when the handset instrument is lifted fromthe mounting- Upon release of the key 23 the bolt 22 will be pressedoutward by its spring and will extend into the path of arm 19. When,however, the handset is placed upon; the mounting and the plunger 15depressed, the arm 19 will be moved downward and come into engagementwith bolt 22 which will be forced out of the path of arm 19 until therounded end portion 20 has passed the bolt 22. Bolt 22 will then bepressedloutward by its spring and hold the arm 19 and plunger 15 againstany upward movement. In this figurethe lock 21 is alsov shown as beingequipped with a catch, handle 29 :of which protrudes through an aperturein an embossing 30 in the base plate 4 and in lane with an aperture 31in the textile base covering shown in cross section at 6. hen the key 23has been turned and the bolt 22 withdrawn from engagement with arm 19,the

in-g between the prongs sa-34.011 a handset mounting the'lock and themeans for securing the base plate to the earml9 and the casing 1together with the switching arrangements are practically identical withthose shown in Fig. '1 with the exception however, that the lock 21 hasbeen placed more to. the rear of thecasing 1 'and the arm 19 has beenturned to be engaged by the lock in that position and thearm 19 insteadof having an oifset portion 20 at itsfr'eeend, has an aperture 32through which the lock bolt 22 is passed. lVith this arrangement, inaddition to more space being allowed in the casing 1 fortheaccommodation :of other apparatus such for i-nstance as a callingdial, should the'lockingarrangement be'used in an automatic substationinstrument. the

plunger 15 is more securely held against upward movement than inthe'construction shown in Fig. '1.

It will be apparent that various changes and modifications'maybe made inthe strucllO What is claimed is:

1. In a telephone instrument, in combination an attached transmitter andreceiver, a mounting therefor having a switch by which telephonicconnection may be had to a telephoneline, an enlarged base portion inthe mounting, and a lock contained within the enlarged base portion bywhich the switch may be locked against operation. 7

2. In a telephone instrument, in combination an attached transmitter andreceiver, a supporting member therefor having an en larged base portioncontaining a switch by which telephonic connection may be had to atelephone line, a lock contained within the enlarged base portion and anextension from the switch to be engaged by the lock.

3. In a telephone instrument, in combination an attached transmitter andreceiver, a supporting member therefor, a base plate in the supportingmember, a switch in the supporting member by which telephonic connectionmay be had to a telephone line, and a lock attached to the base plate ofthe supporting member for locking the switch against operation.

4. In a telephone instrument, in combination a transmitter-receiver, asupporting member therefor, a switch in the supporting member by whichtelephonic sonnection may be had to a telephone line, a plunger in theswitch, an extension piece attached to the plunger and a look within thesupporting member to engage the extension piece on the plun er and lockthe plunger against operation.

In a telephone instrument, in combination an attached transmitter andreceiver, a supporting member therefor, a switch within the supportingmember, a base plate attached to the supporting member, and a lockattached to the base plate and engaging the switch to prevent operation.of the switch.

6. A telephone instrument comprising a transmitter and receiver, asupporting member therefor containing a switch by which telephonicconnection may be had to a telephone line, a plunger in said switch, anextension arm on the plunger and a lock within the supporting memberengaging the exte sion arm to prevent operation of the switch when thetransmitter and receiver are removed from the supporting member.

7. In a telephone instrument, in combination an attached transmitter andreceiver, a supporting member therefor containing a switch, a springoperated plunger in the switch normally depressed by the transmitter andreceiver, an extension piece on the plunger, and a look within thesupporting member, the lock engaging the extension piece on the plungerto prevent operation of the switch when the transmitter and re-

